Detrital zircon dating
As such, they are here designated “detrital zircon facies.” The age ranges present in a given detrital zircon facies (i.e., their recognition criteria) relate directly to known regional source areas of both primary Figure 4 Chronostratigraphic distribution of detrital zircon facies in western North American terranes, as well as referenced samples from the western U. The provenance of PPA facies is either (1) crystalline sources in northwestern Laurentia (Gehrels et al., 1995, 2000), (2) rifted and translated crustal fragments of the Precambrian–Paleozoic northwestern Laurentian miogeocline (Nelson and Gehrels, 2007; cf.
Bradley et al., 2007; Beranek et al., 2010a), or (3) originally peri-Gondwanan/Avalonian crust that was tectonically emplaced along the southern Laurentian margin in early–mid-Paleozoic time and subsequently translated along the plate margin in mid–late Paleozoic time (Wright and Wyld, 2006; Grove et al., 2008).
Supporting evidence for this scale of tectonic control on sedimentary provenance in the ancient rock record exists, but is generally sparse and typically does not document transitional stages of paleotectonics (e.g., Rainbird et al., 1992; Riggs et al., 1996; Dickinson and Gehrels, 2003; Tyrrell et al., 2007; Druschke et al., 2011).
In this paper, my objectives are to use detrital zircon U-Pb data in terranes of western North America to (1) assess long-term provenance links to the Laurentian craton, (2) identify multi-stage sediment sources through time, and (3) emphasize second-order scale observation in detrital zircon U-Pb age studies.
I propose that the transition from MPP to Tr J facies illustrates that, despite retro-arc thrusting and associated elevation gain during Middle Jurassic time (Wyld, 2002; Fuentes et al., 2009), there was not a contiguous mountain belt (i.e., topographically integrated) along the Pacific margin until Late Jurassic–Early Cretaceous time. Instead, sediment sources to marginal basins became restricted to active arc and older igneous basement rocks in the now high-standing continental-margin, Andean-type arc. Syndepositional, suprasubduction compression of the Galice basin in the western Klamath Mountains (Snoke, 1977; Wyld and Wright, 1988; Harper et al., 1994) may represent the earliest manifestation of plate reorganization. My interpretations would not be possible without the work of W.
According to this model, continental-scale drainage patterns in the western U. were reversed between Late Jurassic–Early Cretaceous time and transcontinental sands no longer entered western U. This compilation of detrital zircon U-Pb age data supports the idea of a “common origin for coeval strata on differing basement terranes” (Miller and Saleeby, 1995, p.
These age distributions vary systematically based on the depositional age and tectonic setting of the basin (cf. Figure 1 Map illustrating present-day location of terranes discussed in this paper, age distribution of Laurentian Precambrian crust, and detrital zircon sample locations: SEYTT—Southeastern Yukon-Tanana terrane; YTT-CM—Yukon-Tanana terrane in Coast Mountains; GRAV—Gravina Belt; MT—Methow-Tyaughton; EFLC—Easton-Fidalgo-Lummi-Constitution; YA—Yellow Aster; IG—Ingalls Graywacke; T-N—Tonga-Nooksack; LM—Lookout Mountain; CH—Coon Hollow; BT—Baker terrane; MI—Mitchell Inlier; SL—Snowshoe and Lonesome fms.; KRC—Klamath River Conglomerate; GAL—Galice; AMQ—Antelope Mountain Quartzite; EHT—Eastern Hayfork terrane; NFT—North Fork terrane; U-GVG—Upper Great Valley Group; T-GVG—“Tithonian” Great Valley Group; LDC-P—Lang-Duncan-Culberton allochthons and Picayune Valley Fm.; M-GVG—Middle Great Valley Group; MAR—Mariposa; JEK—Jurassic–Early Cretaceous; MPP—Mixed Proterozoic and Phanerozoic; and PPA—Paleoproterozoic and Archean. Adapted from Gehrels (2001); Wyld and Wright (2001); De Graaff-Surpless et al. (2006); Brown and Gehrels (2007); Nelson and Gehrels (2007); base modified from Whitmeyer and Karlstrom (2007).Thus, rocks bearing PPA facies may reflect sediment derivation from northwestern Laurentian sources enhanced by plate-margin magmatism or multicycle sediment reworking and tectonic translation of crustal fragments allochthonous to western North America.